Locking lamp



March 9 1926.

' H. HUBBELL LOCKING LAMP Filed March 26, 1925 v f Patented Mar. 9, 1926.

lit

UNITED STATES PATENT-OFFICE.

HARVEY HUBB LL, or nnrnoaronr, oonnno'rxcu'r.

LOCKING LAMP.

Application filed March 26, 1325. Serial No. 18,443.

To all whom it may concern:

Be it known that I, HARVEY HUBBELL, a citizen of the United States, residing at Bridgeport, county of Fairfield, State of Connecticut, have inventeda new and useful Locking Lamp, of which the following is a specification.

This invention relatesto electric lamps, and has for its general object to provide'a lamp which may be readily attached to a lamp socket, but which when in place cannot be removed from the socket without rendering the lamp useless, to thus discourage theft and changing of lamps by an unauthorized person.

It is old in electric lampsto so construct the lamp basethat it cannot be removed from the socket without breaking one of the connect-ions from the terminals to the filament. This type of lamp, however, is unreliable because there is no positive assurance that the connection will be broken since this connection may stretch of yield, or, due to the inaccuracies of manufacture, the connection may be too long so that the relative movement between the elements on the base which is depended upon to break the connection may not be suliicent'to produce this effect.

To overcome theseobjections I have devised a construction in which, instead of relying on means for breaking the connection from one of the terminals to the filament,.I so mount the terminals that in normal oporation they will engage the contacts within the lamp socket, but instrumentalities are provided which operate upon and by the operation of removing the lam from the socket to positively move one 0 the terminals to a position where it cannot engage its contact in the socket, with additional means to prevent return of this terminal to its original position, so that after the lam has once been removed from the socket it will be useless. Thus the lamp is so constructed that itmay be screwed into an ordinary lamp soz' ket but cannot be unscrewed therefrom without first performing an operation which will destroy the usefulness of the lamp. V

lVith these and other objects in view, I have devised the construction illustrated in the accompanying drawing forming :1 art of this specification, similar reference c aracters being employed throughout the varithe lamp destroyed, and

Fig. 1 is a side elevation of the lamp with my invention applied thereto. I Fig. 2 is a vertical central section through the base of this lamp showing the position of the elements before it has been applied to a lamp socket. 0

Fig. 3 is a transverse section substantially on line 3-3 of Fig. 2-.

Fig. 4 is a top plan view thereof.

Fig. 5 is a verticalsection similar to Fig. 2 but showing the base after it has been removed from the socket and the usefulness of Fig. 6 is a transverse section of the substantially on line 6-6 of Fig. 5.

The lamp comprises 'the usual glass bulb 10 of any desired shape enclosing any suitable filament 11. Mounted on this bulb is the SZIIIIE base which comprises an inner metal ferrule or shell 12 secured to the glass bulb by any suitable means such as plaster of Paris 13 or the like, and this ferrule is electrically connected to one end of the filament by the conof the socket in the ordinary manner. This outer ferrule is formed with a recess 17 in the top wall thereof with an opening 18 through this recess, and an insulating button 19 is seated in the recess and engages the end of the ferrule. This button has an opening 20 therethrough which is preferably enlarged at itsupper end as shown at. 21 to form a recess. The inner ferrule 12 is provided with an opening 22 in the top wall thereof, and a fibre disc 23 is mounted under this opening between the end wall of the ferrule and the plaster of Paris filling 13 to thus close the opening 22. and this disc may be secured tothe ferrule by means of integral. lugs or ears 2% extending through the disc and bent over on the inner side thereof as shown in Fig. 2.

Carried by the button 19 is the central or end terminal 25 which is ele;:trically connected to the other end of the filament by the connection 26. This contact in the construction shown is a metal disc having a plurality of laterally projecting ears or lugs 27, and the disc is cupped slightly as shown in Fig. 2 so that it will seat in the end of the enlargement or recess 21 with the ears or lugs 27 resting on the end wall of the button 19 to retain this contact in position as shown in Figs. 2 and 4. The disc or terminal is of this element are spun over on the opposite walls to securely connect the disc 25 to the disc 23. The connection 26 may be conveniently passed through this tubular element and secured to the outer end thereof and the disc 25 by turning its end thereof over in contact therewith and soldering it to the two elements as shown at 29.

Secured to the side wall of the outer ferrule 15 is a bowed spring element- 30, reonvenient means of securing this element to the ferrule beinga rivet 31. This spring in the normal position of the elements, as shown in Figs. 2 and 3, extends between the side walls of the ferrules 12 and 15with its free end 32 curved outwardly and projecting through an opening 33 in the outer ferrule 15 so that this free end can engage the inner wall of the screw shell contact in the lamp socket when thelamp is in position therein. Also secured to the side wall of the outer ferrule 15 is another bowed spring 34 secured to the ferrule inthe same manner by means of a rivet, 35. This spring also 'extends between the side walls of the ferrules when the lamp is in the normal working po-' sition as shown in Figs. 2 and 3, but it does through the outer ferrule as doesf not project the first spring. Both of these springs are so mounted that they tend to move inwardly toward the center of thelamp for a purpose provided with .wall of the inner presently to be described. The spring 34 is an inwardlyextend ng lug 36 forming ashoulder which is in alignment with. shoulder 37 produced by cutting and punching laterally a portion of. the side I ferrule 12, and these shoulders are located in alignment when the elements are in the position shown in Fig.2, so

that when turning the lamp'bplb to the right or clockwise in screv'ving' it into the socket the shoulder 37'Wlll engage the lug 36 and will rotate the outer ferrule 15 to screw it into the socket. The end 32 of the spring 30 will slide along the inner surface of the screw shell during this operation. The electrical connections are formed by the engagement of the outer. ferrule 15'w1th the screw shell contact of the socket and the end terminal 25 engaging the central contact of the socket as'is the usual operation.

Should, however, an attempt be made to unscrew the lamp from the socket by rotating the bulb to the left orcounterclockwise the sharp edge of the free end 32' of, the spring 30 will bind against the inner surface of the screw shell and will prevent the outer ferrule 15 turning in a direction to unscrew it from the socket. The lamp is thus locked in the socket. The inner ferrule 12 is, however, free to turn in this direction in the a direction to'unscrew it from the socket these lugswill engage. and will rotate the outer ferrule 15 in this direction to unscrew it from the socket. As the bulb and the inner ferrule 12 move downwardly to the position shown in Fig. 5 the inner ferrule will move from engagement with. the springs 30 and 34 so that both of these springs will spring inwardly toward the center and "over the upper end of the inner ferrule as shown in Figs. 5 and 6. The inward movement of the free end 32 of the spring 30 will carry it out of engagement with the inner Wall of the screw shell and will thus unlock the outer ferrule so that it may be rotated by coaction of the lugs 38 and 39 to unscrew it from the socket.

During this longitudinal moyement of the inner ferrule and bulb as just described the fibre disc 23 is carried downwardly with the inner ferrule and the pull of this disc through the tubularelement 28 .draws the end or central terminal 25 into the enlarged pper portion 21 of the. opening 20 in the nsulating button 19 to the position shown in Fig. 5, the .ears or lugs 27 yielding up wardly and inwardly to allow this movcg ment. It will be obvious that while in this position the end or central terminal is drawn away from its contact in the socket and to a position where it cannot engage this contact,

huttheconnection of this terminal to the filament is not broken. been removed from the socket, which operation of removal as described above-brings the elements to the position shown in Figs.

After the lamp has- 5 and 6, it will be impossible to return them i to their original positions shown in Figs. 2,

3 and 4, and thus the usefulness of the lamp is destroyed. It is tobe' noted that the usefulness of the lamp is destroyed without breaking theconne'ction of either of the terminals with the filament, and that the operation of drawing the end terminal 25 into the opening in the button is a positive action which cannot fail. As the spring 34 is entirely within the outer ferrule it is inac cessible from the outside of the ferrule, and therefore, cannot be retracted to allow movement of the elements to the original posithe opening 33 to swing the spring 30 outwardly. The lower end of the outer ferrule 15 is provided with'a'n inturned flange 40 which engages the rib 41' on the inner ferrule to limit the downward movement of this inner ferrule. The inner ferrule is also provided with outwardly extending ears or lugs 42 just below this rib which will pass the inturned flange 41 when the bulb is drawn downwardly, and" they will then spring outwardly to the position shown in- Fig. 5 to engage the flange and assist the springs and 34 in preventing the return of the elements to the original position of Fig. 2. It will be noted that when the bulb and inner ferrule or shell are moved to the position shown in Fig. 5, the lugs 36 and shoulder 39 are no longer in alignment so that the base cannot be again screwed into a socket as there is nothing to turn the outer shell in the required direction.

Having thus set forth the nature of my invention, what I-claim is:

1. An electric lamp comprising a. bulb and a filament, end and screw shell terminals, connectionsgfrom said terminals to the filament, a support for the end terminal arranged to supportthe terminal in a position tobe engaged by a contact in a lamp socket, and means for moving said terminal into the support Where it cannot engage said contact,

said means constructed and arranged to come into operation'upon and .by the removal of the lamp vfrom 'thesocket.

2. An electric lamp comprising a bulb and a filament, end and screw shell terminals, connectionsfrom the terminals to the filament, means for supporting the end ter-- minalin position to he engaged by a contact in a lamp socket, and means for moving said terminal from said position by movement relative to its supporting means so that it cannot engage said contact, said means con;

.structed and arranged to come into operation upon and by the removal of the lamp from the socket. v

3. An electric lamp comprising a bulb and a filament, end and screw shell terminals, connections from theterminals'to the fila- .1nent, means for supporting the end terminal in position to be engaged by a contact in a lamp socket, means for moving said terminal from said position so that it cannot engage sa1d contact, said means constructed antler-ranged to come into operation upon' and by the removal of the lamp from the ranged to support the terminal in a position to be engaged by a contact in a lamp socket, means for moving said terminal into the support where'it cannot enga e said contact, said means constructed an arranged to come into operation upon and by the removal of the lamp from the socket, and

'means to prevent return of the terminal to its original position.

5. An electric lamp comprising a bulb, an

lamp socket, an inner ferrule longitudinally movablein the outer ferrule and secured to said bulb, an insulating'button carried by the outer ferrule and having a recess therein, and an end terminal-carried by said button in position 'to engage a contact in a lamp socket, and connected to the inner ferrule so that it will be drawh into said recess away from the contact upon longitudinal movemcnt of the inner ferrule.

6. An electric lamp comprising a-bulb, an outer ferrule adapted for attachment to a lamp socket, an inner ferrule longitudinally mova le in the outer ferrule and secured to said 'ulb, an insulating button carried by .the outer ferrule and provided with an openouter ferrule adapted for attachment to a l ing, an end terminal carried by said button in position to engage a contact in a lamp socket and connected tov the inner ferrule so that it will be drawn into said opening away from the'contact by longitudinal movement of the inner ferrule, and means to prevent return of the terminal to its original posi: tion.

7.. An electric lampcomprising a bulb, an outer ferrule adapted for attachment to a lamp socket, an inner ferrule longitudinally-movable in the outer ferrule and secured to said bulb, an insulating button carried by the outer ferrule and provided with an opening, an end terminal carried by the but ton at the outer end of said opening, said terminal being provided with laterally pro jecting' lugs engaging the-end of the but ton, and a tubular element connecting the contact with the inner ferrule, said lugs being adapted to yield to allow the end, terminal to be drawn into saidopening by longitudinal movement ofth'e ferrule.

8. An electric lamp comprising a bulb, an outer ferrule adapted for attachment to a lamp ,socket, an inner ferrule longitudinally movable 1n the outer ferrule, and secure'l to said bulb, an insulating button carried by the outer ferrule and provided with an opening. an end terminal carried by the button at theout'er'end of said opening, saidterminal being provided with laterally pro- 'jecting lugs engaging the end of the button, a tubular element connecting the con-- tact with the inner ferrule, said gs being adapted to yield to allow the end terminaf' to ,be drawn into said opening by longitudinal movement of the ferrule and means to prevent return of the terminal to its original means operatively connecting said shells for rotation in an opposite direction at each extreme of the longitudinal movement of the inner, shell to permit the lamp to be secured in or removed from the lamp socket, and

means operable by longitudinal movement of the inner shell to move the end terminal toa position where it cannot be engaged by its socket contact, I

10. An electric lamp comprising a bulb and a lamp base, said lamp base including an outer shell adapted for attachment to a lamp socket, an end terminal at the outer end of said shell inposition to engage a contact in a lamp socket and insulated from said shell, an inner shell longitudinally movable in the outer shell and secured to said bulb, means operatively connecting said shells for rotation in an opposite direction at each extreme of the-longitudinal movement of the inner shell to permit the lamp to be secured in or removed from the lamp socket, means operable by longitudinal movement of the inner shell to move the end terminal to a osition where it cannot be engaged by 1ts socket contact, and means to prevent longitudinal movement of the inner shell in the opposite direction to prevent return of the end terminal to its original position.

1'1. An electric lamp comprising a bulb and a lamp base, said lamp base including an ,outer shell, an inner shell fixed to the bulb and rotatably and longitudinally movable relatively to the outer,-shell, an insulating button carried by the outer shell and having an opening therein, an end terminal carried by the button in position to'engage a contact in a lamp socket, means connecting said shells and operative when the bulb is turned in one direction to cause engagement of the outer shell with a lamp socket, and inoperative when the bulb is turned in the opposite direction without longitudinal movement and causing removal of the'lam'o when turned in 'the opposite direction after lon itudin'al movement, means connecting inner shell, and means to prevent return ofsai inner shell and the end terminal to draw the terminal into the opening in the button upon longitudinal movement of the the shell and terminal to their original po sitions.

12.. An electric lamp comp rising a bulb and a lamp base, said base including an socket, a spring secured to the outer shell and arranged to engage the socket to prevent removal of the outer shell therefrom, said spring being arranged so that it is held in effective holding position when the shells are in lampsecuring position and released when the shells are inlamp removing position, an insulating button carried by the outer shell and having an opening therein, an end terminal carried by said button in position to engage a contact in the lamp socket, and means connecting the terminal to the inner shell to draw the terminal into the opening on longitudinal movement of 13. An electric lamp comprising a bulb and a lamp base including inner and outer shells adapted for relative movement, the inner shell being secured to the bulb and the outer shell being adapted for. attachment to a lamp socket, an insulating button carried by the outer shell and having an opening.

therein, an end terminal carried by said button in position to engage a contact in the lamp socket, an insulating disc carried by thejnner shell, and a positive connection from the disc to the terminal to draw the terminal into the opening away from its contact by and upon manlpulation of the bulb to remove it from the socket.

14. An electric lamp comprising a bulb and a lamp base including inner and outer shells adapted for relative movement, the inner shell being secured to the bulb and the outer shell being adapted for attachment to a lamp socket, an insulating button car-' ried by the outer shell and having an openmg therein, an end terminal carriedby said button in position to engage a contact in the lamp socket, an insulating disc carried by the inner shell, a ositive connection from the disc to the terminal to draw the terminal into ,the opening away from its contact by and upon manipulation of the bulb to remove it from the socket, and means to prevent return of the terminal to its original position.

ton carried by the outer shell and having an opening therein, an end terminal carried by the button in position to engage a contact in the lamp socket and having laterally extending yieldable lugs engaging the button, an insulating disc carried by the inner shell, and a positive connection from the disc to the terminal to draw the terminal into the opening away from its contact by and upon manipulation of the bulb to remove it from the socket.

16. An electric lamp comprising a bulb and alamp base including inner and outer shells adapted for relative movement, the

inner shell being secured to the bulb and the outer shell being adapted for attachment to a lamp socket, an insulating button carried by the outer shell and having an opening therein, an end terminal carried by the said button in position to engage a contact in the lamp socket, a positive connection from the terminal to the inner shell to draw said terminal into the opening away from its contact by manipulation of the bulb to remove it from the socket, and automatically operable means to prevent return of the terminal to its original position.

17. An electric lamp. comprising a bulb and a filament, a pair of terminals connected to said filament and arranged for engage- 1 ment with the contacts of a lamp socket, means for moving one of said terminals from its position so that it cannot engage its contact, said means constructed and arran ed to come into 0 eration u on and 2 by the removal of the lamp from the socket, and means to prevent return of the terminal to its original position.

In testimony whereof I afiix my signature.

HARVEY HUBBELL. 

